The invention concerns an adjustable armrest for chairs, especially suitable to be applied to office chairs.
As it is known, armrests for chairs are formed by an armrest element that is supported by an upright element connected to the seat through appropriate fixing means.
Some types of chairs are provided with armrests that are adjustable in height in order to adapt the rest position of the arm according to the user""s needs.
The chairs must have a size and a shape in keeping with specific national and/or international sets of rules.
There are for example specific sets of rules concerning the distance of the front end of the armrest element as regards the front end of the seat.
In particular the regulation ANSI BIFMA prescribes that such distance must not be shorter than 100 mm.
Besides the set of rules NEN, in force in Holland, establishes instead for such distance a minimum value of 200 mm.
The necessity of respecting these different sets of rules compels the builders to realize the same chair model with the armrests placed at different distances.
In order to obtain these conditions, it is necessary to provide on the seat, or anyway in the hooking points of the armrest fixing means, for differentiated perforations, so that the same chair model can receive the same armrest model however fixed in different positions.
The aim the present invention is to obviate to the said drawback.
In particular an aim of the invention is that of realizing an armrest allowing the chairs equipped with it, to be in keeping with the sets of rules, in force in the different countries, as for the distance of the front end of the armrest element as regards the front end of the seat.
The said aim is attained through the realization of a seat for a chair that according to the main claim, includes an upright element substantially vertical provided in the lower part with fixing means to a seat of said chair and supporting in the higher part an armrest element, and wherein said upright element and said armrest element are coupled through sliding means suitable to allow the movement of said armrest element in order to vary the distance of the front end of said armrest element as regards the front end of said seat.
According to a preferred embodiment, said sliding means are formed by an annular edge bordering said higher part of said upright element, which is housed slidingly in a guide track obtained inside said armrest element.
Suitable locking means allow to fix the armrest element in the reached position.
Advantageously the invention allows to standardize the production without providing for differentiated perforations of the seat in order to fix the armrest at different distances as regards the front end of the seat. In such a way the same chair with the same armrests is in conformity with the different sets of rules in force in different countries.
Still advantageously the possibility of regulating the position of the armrest can be useful to insert partially the seat under the desk, when its height is lower than the armrest one.